Since the first installer came out, others who came after him have given me new ideas and I’d like to see what the first guy 1) thinks of their viability and 2) would charge if he designed something similar. The original plan he put together was based on my stated preference for a high-temp hydronic unit to power baseboards in the basement and in a one-room/two-story addition on the back of the house, with an option to add an air handler to provide cooling to the upstairs through existing furnace ducts. This was because I need to replace the boiler ASAP and wanted to avoid paying for a new distribution system to the basement and addition which would get pricey. But I recently discovered there are blocked off furnace vents in the basement, which creates the possibility they could be unblocked, heating the basement by the furnace instead of the baseboards, and leaving just the two small rooms in the back addition that don't have ducts. The addition on the back of the house is pretty small, less than 200 sq ft per floor, so I might be able to afford to put radiant flooring with so little square footage compared to the entire basement, and that would allow for a more-efficient lower-temp hydronic unit. Or third idea, if radiant flooring is still too pricey I could get mini-splits for those two rooms and just get a W2A geo unit, potentially even some kind of dual-fuel setup that could hook into my existing gas furnace to heat the entire house through the splits + furnace ducts, and use the gas furnace as back-up/emergency heat for very cold days. So, these are very different ideas with different costs and makes the first guy's proposal hard to compare. He was actually my favorite from an industry experience/communicativeness/demeanor standpoint, so I want to keep him in the running, but I also want to be respectful of his time and not annoy him by asking for change after change after change when I haven't paid him anything yet. How many revisions/updates is it appropriate to ask for, and is it better to save them up to request all at once or to stay in dialogue with him and talk through new ideas as they come to me?
My ideas get farmed out all the time on bids. I live with it. We all do. If you let him know how serious you are in moving forward, I can't see there being any issue at all.